To add a video for Carl Tausig / Adagio (after Beethovens Adagio molto e mesto from String Quartet Op. 59/1), just enter the video‘s YouTube link:
example) https://www.youtube.com/watch?v=XXXXXXXXXXX
Search YouTube for Carl Tausig / Adagio (after Beethovens Adagio molto e mesto from String Quartet Op. 59/1)